Vehicle occupant recognition systems (ORS) are useful in connection with air bags and other pyrotechnically deployed restraints as a means of judging whether, and/or how forcefully, to deploy the restraint. Ideally, the system should be capable of classifying the type of occupant (i.e., large adult, small adult, child, etc.) and determining if the occupant is out-of-position relative to the point of deployment of the air bag. Various systems incorporating one or more infrared and/or acoustical ranging sensors have been proposed for this purpose; see, for example, the U.S. Pat. Nos. 5,330,226 and 5,785,347. In general, such systems emit one or more beams of infrared energy to define a corresponding number of viewing fields, and receive the reflected energy to detect the presence of an occupant within the viewing fields.
Typically, the ORS must have a high speed of response so that deployment can be properly inhibited or allowed when the occupant position quickly changes. However, such systems require a large amount of data to reliably perform the classification and position detection functions, and the update rate of the detected position is usually slower than desired for purposes of determining whether the occupant is out-of-position. Accordingly, what is needed is a control method for augmenting the discrete position measurements provided by the ORS so that deployment can be reliably inhibited or allowed in a more timely manner.